I have a set of 416 305 heads that I want done for my 350 engine. I thinking about getting the intake valves off the 350 heads which are 1.94 inch put in the 416 heads. Have the heads dipped and everything, milled to 53cc ( is this too much to mill it ) , and fully ported, and assembled. Im thinking that all this will cost me about $250. Is this a correct estimate. Also, I heard that when you mill heads the ports on the heads don't match up with the ports on the intake manifold and gives trouble. Will milling them to 53cc be too much of a difference in height. Also, if the 416's are fully ported they should make good power right?

 

No.

You will be hard-pressed to get a standard "rebuild" done to a set of heads for $250.

Expect another $100 or so for the cheeeeeepest possible 1.94" valves, another $150 or so to have them cut in, and the sky's the limit for the port work to actually make that accomplish something.

Then of course it'll cost you for miulling for guide plates and screw-in studs, cutting the valve guides down for Teflon seals, cutting the spring pockets for larger springs, and lengthening the push rod slots for 1.6 rockers. Expect that by the time you get done with all that, you'll have about $750 in those heads, plus porting; I do all my own porting myself so I can't say how much somebody would have to pay somebody else to do it for them since I'm not that lazy, but I'd charge AT LEAST $100/hr plus materials for porting, and it'd take about 2 hrs to minimally port those heads to accept those valves, plus about $20 of abrasives.

You will find, if you just jam the larger valves in those heads without doing anything else, that the flow will actually GO DOWN because the intake valve margin (edge) is so close to the "vertical" chamber wall. After all, doesn't matter how big the valve is, if all the stuff coming through it then has to squeeze through some narrow crack to get around the edge. Expect that your 58cc heads will go to about 62cc when the chambers are properly opened up to take advantage of the larger valves and for chamber shrouding to cease to be an obstacle to flow.

SBC heads lose about 1cc for every .006" of milling, and as you mill, the chamber gets smaller, so each additional .001" of milling makes less change to the chamber volume. Therefore, to get 62cc heads to 53cc, you'll need to take off roughly .055 - .060". That's almost 1/16". I wouldn't do that, the decks are already thin enough. However, yes at that much milling, you WILL need to cut the intake as well.

All around, not a good plan.

I believe instead of hacking together a bunch of garbage like that, I'd attack the real problem that makes you think you need to eliminate the chamber like you're talking about. Like, get rid of the dog-bowl-dish pistons.

What are your goals for this motor? What are the other parts around the heads? That will shed some light on what the right compromise between $$$$ and speed might be.

 

I have 2 sets of heads. 1 set with 1.94 valves and then the 416's. I was planning on using the 416 heads with the 1.94 valves. Since you said that it will go to around 62cc Ill just leave it at that. that doesn't look like im over doing it right? I guess I'll have to port them myself only I don't know how and I heard that you can over port heads.

How much do youe expect it'll run me to get the heads dips install the 1.94 valves and assembled without milling? Then how much for all that if in theory I got them milled to 57cc? Thanks for all the help. I wanted to mill the heads to atleast get 10.2 compression.

 

I spent around 500 to get my dart heads ported, assembled, intake match,

 

You can get them to make decent power, i have those heads with the 1.94 valve (3 angle job) and some home porting on a very mild hyd cam 350. Car runs 12.29 @109 with those heads...

However, I think I have pretty much hit MY limit with them, instead of putting more $$$ into them, I am going to a set of 195 AFR's.